Core C: Analytical and Phenotyping Core The purpose of the Analytical Core is to provide state-of -the art biochemical analysis of sympathetic function, including measurements of catecholamines, their metabolites, and norepinephrine clearance and spillover. This resource has been critical to the recognition and characterization by our group of new disorders involving the autonomic nervous system, such ads dopamine-beta-hydroxylase deficiency. A variety of techniques have been established in this Core to support individual projects, including the determination of plasma volume and dynamic fluid shifts. All four projects will utilize this resource. Biochemical evaluation of sympathetic activity will complement other methods of autonomic evaluation detailed in the Clinical Core. In addition, we have implemented an animal phenotyping facility, adapting the methods developed to evaluate autonomic function in humans, to the mice. This includes, among others, monitoring intraarterial blood pressure in awake unrestricted mice, monitoring renal sympathetic nerve activity and high fidelity ECG, in intact and sinoartic-denervated mice. Genetically-modified mice are increasingly important in translating autonomic knowledge, and this phenotyping mice laboratory will be essential in this regard.